1. Field of the Invention
The present invention relates to an air conditioner adapted to control the rotational speed, i.e. the number of rotations per unit time of a fan depending on an angle of a flap provided to an air outlet.
2. Description of the Prior Art
Air conditioners conventionally available include one in which a horizontal or vertical flap is provided to an air outlet, the flap being controlled by a stepping motor to thereby change the direction of air blown out through the air outlet. This conventional type of air conditioner has been arranged so that a control of an angle of the flap and that of a fan are carried out independently of each other.
Of such conventional air conditioners, one adapted to control a constant rotational speed for the fan has the following problems. That is, the amount of air flow will increase or decrease depending on a change in blowing resistance due to a change in the angle of the flap. Vapor condensation may in turn occur on the flap or the like. Thus, a change in the shape of the flap and the like may be needed to prevent such an occurrence of condensation. Therefore, the number of design manhours or mold cost increases. In another air conditioner of the conventional type in which rotational speed of a fan is changed depending on a load to thereby control the amount of air flow to a constant, there have been problems such as those described below. That is, since the number of rotations of the fan per unit time will normally vary owing to a change in blowing resistance due to a change in the angle of the flap, a pulsating noise occurs with the air flow. Many manhours are involved in tests for determining constants necessary for load response control or the number of printed circuit boards must be increased to accommodate circuit components to meet the constants.